I'd say that ND - stands for possibly a variation of 'nostrum dominus', 'our lord' X - is for 'Christ' O - could be a cipher, a separator (the two o's stand symmetrical in the inscription, and have an additional stroke, unlike the rest of the letters [with the possible exception of the first C/G) X again for Christ C or G - uncertain, but could be 'clemens', 'gratus', etc. H - could by anything, but perhaps 'hosanna'? W - this could well be an inverted M, an in that case could stand for 'Maria' D and N - if referring to Mary, perhaps 'domina nostra' once more, You got 'n' wrong, and mistook it for 'r'. C/G and H - this sort of monotonous iteration is extremely common with charms D and X - dominus Christus O - separator R - perhaps 'rex' or 'regina' V/U/Y - the initial letter of the sword-bearer's name I - could again be an initial, but could also be a numeral. My two cents. Also, the abbreviations all have precedents and are quite widespread, so...